The bitter battle over union representation for 1,300 state correctional employees -- already marred with charges of corruption -- now is complicated by criminal allegations of burglary and theft.

Michael K. Spiller, a former vice president of the Maryland Correctional Union, was charged during the weekend with breaking into the union office and stealing canceled checks, monthly bills and two computers containing sensitive employee information.

MCU officials said they fired Spiller a week ago after discovering that he had been secretly working for a rival union trying to get the MCU to merge with the American Federation of State, County and Municipal Employees, according to court documents filed yesterday.

Spiller, who denied being terminated because a membership vote had not been taken, vehemently disputed the criminal charges, filed by Herbert Berry, a volunteer staff director for MCU.

He said he had not been served with the criminal summons as of yesterday, but a court date has been scheduled for Aug. 16. He said it is Berry who was terminated from his job. "He is probably the only person who isn't supposed to be on the property," he said.

"This is why I have a headache," said Spiller, who is charged with one count of second-degree burglary and one count of theft. "This is very much a mess. I'm just amazed that [Berry] chose to pick my name. If he made criminal charges, I hope he makes them stick, because otherwise he has a problem here."

The charges are only the latest chapter in what has turned out to be a sordid fight that involves four unions, a flurry of charges and countercharges and the ouster of five board members at an emergency meeting Saturday.

Berry said the other unions "didn't expect MCU to be able to fight as hard as we did. They did not expect the rallying of members and because of that, AFSCME is backing away from their merger deal."

In May, Gov. Parris N. Glendening granted limited collective-bargaining rights to unions representing about 50,000 state employees. An agreement signed this month by the presidents of AFSCME International and the American Federation of Teachers International calls for AFSCME to bargain on behalf of Maryland public-safety employees.

Some MCU board members have said that the intent of the agreement was to kill their 4-year-old union, and that they will oppose it. AFSCME, which represents 2,500 correctional employees in Maryland, would have to be approved in an election to do the bargaining this year.

The fight has spawned allegations of financial wrongdoing by MCU President Mary Kim Howard, who received salary advances totaling $21,059 between November 1994 and November 1995, according to an audit report. Howard -- who on July 9 was fired as an employee of MCU and stripped of her salary, but continues to serve as president of the board that runs the union -- has said the advances were approved by eight board members.

On Thursday, five board members met and demanded that Howard quickly repay most of the $21,000 with interest. Howard, who called that meeting illegal, convened another meeting Saturday and, backed by a general membership vote, ousted those five members, Berry said.

Howard said questions about her pay advances were motivated by AFSCME's attempt to take over representation. In an interview yesterday, Berry claimed that the American Federation Teachers is using the City Union of Baltimore -- which is affiliated with AFT -- "to force us to join with AFSCME."

Berry said he discovered the break-in when a staff member called him Saturday and could not get into the MCU office in the 2500 block of St. Paul St. Berry said he called a locksmith to get inside.

Two computers, two monitors, two printers and two keyboards, along with a box of canceled checks and monthly bills, were reported stolen. Berry said the records include all the union's financial statements and bank records, including account numbers, and a list of every correctional union member. Also missing, he said, were confidential letters and memos between the union and top state officials.

According to the court documents written by Berry, Spiller used false paperwork to persuade a locksmith for Atlantic Lock and Key on Friday night to pick the lock, which Berry said had been changed after Spiller was fired.

Berry alleges that after breaking in, Spiller had the locks changed "hoping that MCU would not be able to open for business" yesterday.

According to a city police report, Berry also charges that Spiller paid the locksmith with checks written by Chester Wilton, president of the City Union of Baltimore and a former staff member of MCU. Berry also charges in the court papers that Wilton "tried to force MCU to shut down by sending faxes to the bank's check service we use, telling them that we are no longer solvent."

Wilton could not be reached for comment yesterday, but a union lawyer, Christyne Kneff, said both he and Spiller will "take all necessary action to clear their name and reputation."

"Mr. Berry has definitely lost his mind, making these unfounded charges against me," Spiller said. "This is really amazing."